


Testing a Hypothesis

by frankie_felony (dextrosinistral)



Category: The Avengers (2012)
Genre: M/M
Language: English
Status: Completed
Published: 2012-08-11
Updated: 2012-08-22
Packaged: 2017-11-11 22:34:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,168
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/483597
Author URL: https://archiveofourown.org/users/dextrosinistral/pseuds/frankie_felony
Summary: <blockquote class="userstuff">
              <p>What ruins a friendship isn't often the thing that seems to be the obvious thing.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [mikes_grrl](https://archiveofourown.org/users/mikes_grrl/gifts).



> A couple of weeks ago I retweeted this: this tweet: “fucking doesn’t mean a friendship ending. its shitty behaviour post-fuck that ends a friendship.”
> 
> Mikey, being the enabler xe is, suggested that that sounded an awful lot like a prompt for some fic, so I wrote it.

He wants to say he doesn't know how he got into this, but that's not even remotely true. He'd been wondering about this for a while, trying to hide his attraction behind sarcasm and silence, but somehow Tony had seen through it. Maybe he'd just made a lucky guess, but that's seriously doubtful. Tony Stark may make light of many things, but at heart he _is_ a scientist and he's not likely to make a guess about something without evidence to back it up.

He realises with a start that his mind is wandering, and Tony's probably going to call him on it in about half a minute if he doesn't get back to the task at hand. He can't help but wonder, though, as his fingers trace the arc reactor, if this is just an experiment for either of them. It's been quite a while, at least for him, and there's a niggling thought in the back of his mind saying that this is probably a terrible idea.

He ignores the thought, lifting his hips to better accommodate Tony's fingers. It's such a foreign sensation, the mild stretching pain not being associated with the stretching of bones and muscles when he becomes the other guy. Soon – too soon? or not soon enough? – he's empty, waiting, but not for long. He bites back a groan, then, as Tony fucks him, fingers leaving bruises on his ribs, and presses his thumbs against the arc reactor, needing something that isn't about to change for a moment.

The thoughts come creeping back as Bruce adjusts to Tony's rhythm, as his hands find soft spots in his sides, dragging finger marks into his ribs. Their banter right after they'd met, the easy grace with which Tony picked on him without crossing the line into dangerous territory, he wonders if that's what started this snowball rolling.

Even now, Tony won't shut up, but Bruce can't bring himself to tell him to, because even though half of it should be reserved for their time in the lab instead of what they're doing now, the other half, he's saying things that nobody has said to Bruce in a long time, and he's being considerate of Bruce's needs, and Bruce really isn't quite sure how much of this he can take. He jacks Bruce off, finding a counter to his own movements, and _god, that's good_ , but the thought of his theory returns, unbidden, turning his orgasm into something bittersweet.

Tony finishes up shortly after him, drops onto the bed beside him, his fingers drawing a lazy trail up Bruce's stomach. "That was great, we should think about doing it again sometime," his voice is soft, in stark contrast to what they had just been doing.

"Yeah," Bruce murmurs, "You've got to test a hypothesis more than once to get sufficient data."

"What?" Tony stills for a moment. "What are you talking about?"

He shakes his head. "Nothing, Tony. Talking to myself, I guess."

"All right," Tony shrugs, moves to get up. "I'll be right back." And he is, cleaning them up and dropping the towel on the floor beside the bed and lying back down. "Hey, maybe in the morning we can work on that thing we were talking about earlier... "

"That sounds good." Bruce only sort of hears what Tony says, starting to nod off already. He didn't think he'd be this sleepy, but already he's barely conscious.

He wakes up when the sun is shining into his eyes, groaning softly and turning away from the window, only to be greeted by a mess of dark hair at about his chest level. He frowns, remembering the events of the night before, and gets out of bed, pulling on his pants and heading for the bathroom, hoping that Tony won't wake up before he gets—

"Bruce?"

 _Shit_. "Good-morning, Tony." His words are careful.

"What's the rush?" Tony sits up. In the daylight, Bruce can see a number of bruises beginning to show up, and he wants to get out even more.

"I have—I need to take care of a couple of things. Do some meditation. You know, usual morning routine stuff." He waves a hand in the air as he finishes, turning once again to the door.

"You coming down to the lab later?" Tony's voice is totally open, and he almost sounds _excited_ to have someone that can share in his joy of building things. Bruce thinks he's imagining that, though; usually Tony is happy to spend that time alone with his bots.

"Yeah. Sure. Give me a couple of hours."

Tony watches him disappear through the door and gets up, a strange feeling settling in his gut. If he's just read that conversation right, he almost thinks Bruce is upset about something. The only problem is, he doesn't know what it is. He shrugs it off and showers, planning out how much he thinks they can accomplish on this latest project if they can get six or seven really good hours in the lab today.

Bruce doesn't show up. The best anyone can tell him is that he left (shortly after leaving Tony's room, it turns out) and hasn't come back yet. So Tony does what he can alone, surmising that he can't be too surprised with Bruce's disappearance, especially given some of his previous experiences in New York. Still, it hurts: he didn't expect to be brushed off that quickly.

Tony spends the day working on another project instead, not wanting to make progress without Bruce on what they've been working on together. It just seems wrong; he'd feel like he was stealing work, and that's not what he does. He gets Dummy to help with some of the work and finds himself talking to his robot like it's a person, _again_. He hasn't been doing that lately, but then, lately he's had a real person to work with and bounce ideas off of, so he hasn't needed to talk to his bots as much.

When he finally comes back up from his lab, late, and heads to the kitchen to get some coffee or _something_ , he finds Bruce sitting at the table with a cup of tea. "Where were you all day? We missed you in the lab."

Bruce raises an eyebrow, giving him a glance. "I told you, I had to take care of some things. They took longer than anticipated." He hates how good he's gotten at lying, but how insecure and exposed he felt last night – how much he _still_ feels it – he hates that more. Tony seems like nothing has changed, and Bruce isn't sure if that makes it better or worse.

"Tomorrow, then?"

"Sure." He can give it a day to settle. Tomorrow has to be better than today, right?

He's feeling more confident until he gets to the lab and sees Tony, sleeveless and sweating, bent over one of his bots, repairing it, and he just wants to touch him. But they've built a tenuous bond as friends, he supposes. It wouldn't be right to take advantage of what is still so fresh and ruin it with suppositions.

"I'm almost done here, if you want to wait a couple of minutes."

"Sure," he grabs a towel and waits for Tony to finish before handing it to him. "Where did we stop the other day?"

Tony clears off some workspace, pulls up their diagrams and schematics, and they get back to work. Bruce finds it easy to forget what had transpired the other day while they're neck-deep in science, until they reach to enlarge something at the same time and their fingers touch. Bruce jerks his hand back as if he's been burned, stammers out some excuse and flees the lab.

Tony frowns, saves their work where they stopped, and debates for a moment whether or not to follow. Eventually he does, catching Bruce just down the hall from the elevator. He reaches out and grabs his wrist. "Bruce, what the hell is going on?"

"I can't right now, Tony." He turns, gently extracts his arm from Tony's grip. "Go back to your lab; work on the suit or something." His voice is placid, but there's something in his eyes that tells Tony to leave him alone.

Tony steps back, "All right. You're welcome back down whenever you're ready to get back to work."

It's over a week before Bruce ventures back down to face Tony again; a tense week filled with awkward silences and sideways looks when nobody is watching. He thinks he's got his insecurity under control when he goes back down, and they manage to get through a few productive days of work before Bruce can't stand the silence any longer. He wants to leave the lab, but he knows eventually Tony will find him again.

A hand waving in front of his face brings him back from his thoughts. "Hey, Bruce? Are we doing this today, or should I give up and work on the suit?"

Bruce shakes his head. "I'm done. You can finish this up yourself, I'm sure. You're a genius." And he turns and leaves before he can be stopped. On his way out, he catches a glimpse of their reflections, and it makes him want to throw up. The pain in Tony's face, his expression of pure heartbreak as Bruce wrecks whatever's left of their friendship, only spurs Bruce to keep going.

He wishes he could turn around and make things better, go back to doing their projects and being awkward almost-but-not-quite-friends. But he knows that he'll only hurt Tony in the end, that it will never work out like he might hope it will. He stops on his way and takes just a couple of things, leaves his phone, and finds his way out of the tower, out of midtown. He has to get out of New York.

He's surprised when, several weeks later, it's Clint who finds him first. Clint, ostensibly alone, apparently unarmed; he doesn't even see him lean back against the coffee bar beside him until he speaks. "You know, we could use you back on the team."

"Did Cap—"

Clint turns his head, meets his eyes, and fixes him with a look. " _Nobody_ put me up to this, Banner. Don't you dare offend me by suggesting otherwise. You didn't go too far, so I'm guessing you're not totally sold on going back into the world by yourself after you've seen that you _can_ , in fact, live with and around people without losing your shit, and you seem to forget that I'm really good at what I do. Do you really think my waiting to approach you was anything other than a courtesy?"

"I had to leave."

"Yeah, sure, whatever, your hulkness, and now you need to come back. We need you. And you need us, even if you won't admit it." Clint straightens back up. "Look, that Mexican restaurant a couple of blocks over? Meet me there in a couple of hours; there's some shit you need to hear, but I'm not going to talk more in this weird-ass place you thought was a good idea for coffee. I'll be waiting. You don't get to say no, this time." And then he's gone. Bruce isn't sure for a moment that Clint was even there, except for the disturbed sugar packets and straws.

Bruce drinks his coffee, considers getting the hell out of dodge again, but then realises that there's not really anywhere he could go. Fury would find him. Clint would find him, for certain; he knows how skilled a tracker the archer is. Trying to run again would be useless if they really wanted to find him. He _does_ wonder why they're not looking for him, though.

He gets to the restaurant later than he thinks Clint would want him to be there, but he doesn't _care_ , not right now. He sees Clint sitting in a corner by an exit, watching the door and talking to the waitress at his table. He makes his way over to the table eventually, takes a seat and looks at Clint. "What?"

Clint just looks at him for a long time and doesn't say anything until after he's brought a plate of food. His attention shifts momentarily to the plate, but then back to Bruce. "What the fuck did you do?"

"What do you mean?"

"Why'd you leave?" Clint's voice is softer now. "You went thorough enough to avoid taking anything that might have a tracking device. What the hell happened that freaked you out so bad?"

"I couldn't stay. Personal stuff. I don't know."

"Bullshit, Banner. You started acting like a dick, and then you left. Did you and Stark get into a fight or something? He hasn't come out of his lab for the last few weeks but he's not even doing anything down there, he's upset about something. So, what the fuck, man?"

Bruce looks away for a long moment, then looks back at Clint. "I don't want to talk about it."

"Too. Fucking. Bad." He has the decency to wait until he gets another cup of coffee before he continues. "I know you two got into it about something. Nobody's saying what, though, that means it's really—" he cuts himself off, makes a peculiar face. "I know what happened."

"Enlighten me."

"You slept with him, didn't you." It's not a question.

Bruce feels a little offended that Clint guessed so easily. "Let's say you're right. Then what? Whatever questionable friendship we had is ruined."

"Why? Because of the sex?"

He lifts a shoulder. "Maybe."

Clint just stares at him, for so long that it's getting really unnerving. He's about to say something when finally Clint speaks. "That doesn't mean your friendship has to be over. What ruins a friendship after two people fuck is when one of them acts really shitty. I wonder which one of you that was."

"It's doubtful he meant anything to come of it, anyway."

"Stop lying to yourself, Banner. If it was just going to be a fuck, do you really think he would've kept doing whatever science shit you guys have been doing together? You need to get the fuck over yourself and apologise. I think this might be salvageable, if you want it to be. I'm not dragging you home; you know where we are when you decide to grow up." He gets up, leaves money on the table to pay for his food, and leaves.


	2. Chapter 2

**Summary for the Chapter:**

> In which Bruce learns that all is not lost.

It's another couple of months before Bruce comes home. It's funny, he thinks, how that stupid tower in midtown so quickly adapted itself to "home" when nowhere else had for so long, when he hadn't _let_ anywhere else be. He's decided that Clint is probably right; he does need to grow up and take responsibility for acting like such a jerk.

It's almost surprising when he can still get right back into the building and JARVIS greets him like he'd only just stepped out. "Good afternoon, Dr. Banner."

Bruce blinks, trying to compose himself. "Uh. Hi, JARVIS. Is it clear to my room?"

"It is. Agents Barton and Romanova and Captain Rogers are out of the building, and Thor is currently off-planet."

"Thanks." He goes to his room and sits on his bed for a long time while he thinks about what he needs to say. When he decides, he gets up and takes a shower, figuring he should probably not show up to apologise to Tony looking like he's been living under a bridge for the past five months.

He stays in the shower longer than he really needs to, but he isn't sure he's going to be able to get to Tony to say anything. Finally he gets out and puts on some clean clothes. "Uh, JARVIS? Is Tony in the lab?"

"Yes, Dr. Banner."

"He doesn't know I'm here, does he?"

"I have not alerted anyone to your presence." JARVIS almost sounds put out that Bruce would suggest such a thing. Bruce shakes his head and heads for the elevator. He doesn't really think he's going to get in, but it can't hurt to try, right?

He gets down to Tony's lab and half-heartedly gives his authorisation to get in. He is utterly astonished when the door opens without a moment's hesitation. He steps inside and the door shuts behind him. Tony is still bent over something at his workbench, his back to the door. The music is so loud Bruce can barely hear himself think, but Tony hasn't seemed to notice his entrance.

Bruce cautiously walks across the lab and shuts the music off. Tony stops, turns – as if he's getting ready to reprimand JARVIS or Dummy for turning the music off – and stops dead, staring at Bruce. His expression contorts from annoyed to angry, to hurt, finally settling on confused. "Do you have a minute?" Bruce asks, trying for an in.

"Not sure. I'm kind of busy here." Tony starts to turn back to the bench.

"I want to apologise, Tony. Do you have time for that?" He keeps his tone quiet, unassuming. He doesn't want to push Tony further now.

It's strangely satisfying to watch Tony stop mid-turn. "I'm listening."

"I'm sorry I was a jerk. I don't know what I thought after we... slept together... but I guess it was that our friendship would dissolve. And I didn't want that, but if it was inevitable I might as well hurry it on, right? Save us both the trouble." He takes a breath, then continues. "I just... You came in, and read the files and bothered to try to get what I was doing, and you never walked on eggshells around me, and it was such a change from the usual. I guess I fell for it. For you. But you haven't really—you don't really do the relationship thing, even with Pepper it didn't work out, and she has worlds more patience than anyone I've ever known. What hope is there for me, then? I didn't think that was something I wanted, but then you said... "

He trails off when realises Tony is just staring at him like he's an idiot. "When I said, 'hey, I think we should sleep together', I didn't mean 'and then not be friends in the morning'. I really thought you'd say no."

"Well, I like you, Tony. I don't know what it means for us as friends or teammates or anything, but I'd like to not sacrifice what we've made, if it's not too late. Can we rebuild this?"

There's a long silence while Tony considers it. "I think so. It might take a while, and it's probably going to be frustrating. Are you prepared to handle that?"

"Yeah, I am." He's faintly surprised how easily the words come.

Tony pulls up their project, still in the same place it was when Bruce had left. "Good, 'cause we have a lot of work to do."


End file.
